The present application is based on Japanese Patent Application No. 2001-177292, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
This invention relates to a half-fitting prevention connector in which when a pair of male and female connector housings are fitted together, a half-fitted condition of the male and female connector housings is detected by determining whether or not a fitting detection member, mounted on one of the connector housings, can be slid into a proper fitting detection position.
2. Related Art
In a conventional half-fitting prevention connector shown in FIGS. 7 and 8, when a pair of male and female connector housings 1 and 9 are fitted together, a half-fitted condition of the male and female connector housings 1 and 9 is detected by determining whether or not a fitting detection member 2, mounted on the male connector housing (first connector housing) 1, can be slid into a proper fitting detection position (see JP-A-8-31517).
As shown in FIG. 8, the male connector housing 1 has a flexible lock arm 4 rising from an upper wall 3 at a front end thereof and further extending toward a rear end of the housing, and a lock portion 6 is formed on an intermediate portion of an upper surface of this flexible lock arm 4 in a projected manner.
A pressing plate portion 7 is provided at a free end of the flexible lock arm 4 disposed near to the rear end of the male connector housing 1, and this pressing plate portion 7 serves as an operating portion for elastically displacing the flexible lock arm 4 when fitting the male and female connector housings together.
The female connector housing 9 has an engagement portion 10 formed on an inner surface of an upper wall thereof at a front end thereof which upper wall overlies the flexible lock arm 4 when fitting the male and female connector housings 1 and 9 together.
As shown in FIGS. 9 and 10, when the length of fitting of the male and female connector housings 1 and 9 relative to each other reaches a proper value, the engagement portion 10 slides over the lock portion 6 through the elastic displacement of the flexible lock arm 4. When the length of fitting of the male and female connector housings 1 and 9 reaches the proper value, the engagement portion 10 becomes engaged in a recess 6a, disposed at the rear side of the lock portion 6, from the upper side, to retain the lock portion 6, thereby locking the male and female connector housings 1 and 9 in a fitted condition.
As shown in FIGS. 7 and 8, the fitting detection member 2 includes an operating plate portion 16, which is slidably engaged with the pressing plate portion 7 so as to slide in a fitting direction of the male and female connector housings, a resilient piece portion 17, extending from a rear end of the operating plate portion 16 toward the front ends of the male and female connector housings, and a positioning retaining portion 20 formed at a distal end of the resilient piece portion 17 in a projected manner, these portions being formed integrally with one another. The resilient piece portion 17 has a bar-like shape, and can pass through a space between a pair of side plate portions 5 and 5 of the flexible lock arm 4.
As shown in FIG. 7, the positioning retaining portion 20 is in the form of a projection, and can be fitted into each of recesses 6a and 6b, disposed respectively at the rear and front sides of the lock portion 6, from the lower side by the resilient force of the resilient piece portion 17. Before the male and female connector housings are fitted together, this positioning retaining portion 20 is kept fitted in the recess 6a at the rear side of the lock portion 6, and is retained by a rear edge of the lock portion 6, and therefore is prevented form forward movement.
The position where the positioning retaining portion 20 is abutted against the rear edge of the lock portion 6, and is prevented from forward movement is an initial position of the fitting detection member 2 mounted on the male connector housing 1.
With respect to the sliding engagement between the pressing plate portion 7 and the operating plate portion 6, the sliding range is so determined that the fitting detection member 2 can slide between the proper fitting detection position, set forwardly of the above initial position, and this initial position.
When the pair of male and female connector housings 1 and 9 are fitted together, the length of fitting of the male and female connector housings 1 and 9 reaches the proper value, so that the engagement portion 10 is fitted in the recess 6a at the rear side of the lock portion 6, as shown in FIG. 10.
Therefore, the positioning retaining portion 20 of the fitting detection member 2, already fitted in the recess 6a, is downwardly pushed out of this recess by the engagement portion 10, so that the holding of the positioning retaining portion 20 in the initial position is canceled. As a result, the fitting detection member 2 can be slid by pushing the operating plate portion 16 forward as indicated by arrow A in the drawings.
When the fitting detection member 2 is pushed forward after the holding of the positioning retaining portion 20 in the initial position is canceled, this positioning retaining portion 20 moves forward in sliding contact with the lower surfaces of the engagement portion 10 and lock portion 6, as shown in FIG. 11. Then, when the positioning retaining portion 20 moves past the front edge of the lock portion 6, this portion 20 is displaced upwardly by the resilient force of the resilient piece portion 17, and is fitted into the recess 6b at the front side of the lock portion 6.
Therefore, the positioning retaining portion 20, thus fitted in the recess 6b, is retained at its rear end surface by the front end surface of the lock portion 6, and is held in a locked condition, that is, prevented from rearward sliding movement.
However, if the length of fitting of the male and female connector housings 1 and 9 does not reach the proper value, thus inviting a half-fitted condition, when the male and female connector housings 1 and 9 are fitted together, the engagement portion 10 of the female connector housing 9 will not be fitted into the recess 6a at the rear side of the lock portion 6.
Therefore, the positioning retaining portion 20 will not be pushed out of the recess 6a by the engagement portion 10, and therefore the holding of the fitting detection member 2 in the initial position by the lock portion 6 will not be canceled.
Therefore, in the half-fitted condition of the male and female connector housings 1 and 9, even when the operating plate portion 16 of the fitting detection member 2 is pushed forward, the fitting detection member 2 will not be moved forward, and therefore the half-fitted condition can be detected by determining whether or not the fitting detection member 2 can be moved forward.
After the male and female connector housings 1 and 9 are fitted together, the operating plate portion 16 of the fitting detection member 2 is exposed, and therefore there was encountered a problem that when an external force of above a predetermined level acted on the operating plate portion 16 from the upper side, the flexible lock arm 4 was elastically deformed (since a deflection space was provided between the flexible lock arm 4 and the male connector housing 1), so that the locking of the male and female connector housings 1 and 9 to each other was canceled.
This invention has been made in view of the above problem, and an object of the invention is to provide a half-fitting prevention connector in which the deflection of a lock arm is prevented in a completely-fitted condition, thereby stably maintaining the fitted condition.
The above object has been achieved by a half-fitting prevention connector of the invention of claim 1 which comprises:
a first connector housing having a flexible lock arm;
a second connector housing which has an engagement portion for engagement with a lock portion of the flexible lock arm, and is connected to the first connector housing by the engagement of the lock portion with the engagement portion when the second connector housing is fitted relative to the first connector housing; and
a fitting detection member which is mounted on the first connector housing so as to slide in a fitting direction of the first and second connector housings, a half-fitted condition of the first and second connector housings being detected by determining whether or not the fitting detection member can be slidingly moved; characterized in that:
the fitting detection member includes a detection member body, which is fitted on an outer periphery of the first connector housing so as to slide in the fitting direction of the first and second connector housings, a positioning retaining portion for engagement with the lock portion to hold the detection member body in an initial position, and a deflection prevention rib which is formed at a rear end of the fitting detection member so as to prevent the deflection of the lock arm in a completely-fitted condition;
when the first and second connector housings are completely fitted together, the positioning retaining portion is pushed out of the lock portion upon engagement of the engagement portion with the lock portion, so that the engagement of the positioning retaining portion with the lock portion is canceled; and when the detection member body is slid from the initial position to a proper fitting detection position generally near to a front end of the first connector housing, the positioning retaining portion is engaged with a detection member-retaining portion, formed at a distal end of the lock arm, thereby holding the fitting detection member in the proper fitting detection position, and also the deflection prevention rib is slid under the lock arm to prevent the deflection of the lock arm.
In the half-fitting prevention connector of the above construction, the deflection prevention rib for preventing the deflection of the lock arm in the completely-fitted condition is formed at the rear end of the fitting detection member mounted on the first connector housing, and when the completely-fitted condition is achieved, the deflection prevention rib slides under the lock arm to prevent the deflection of the lock arm. Therefore, even when a load is applied to the lock arm, the locked condition will not be canceled, thereby stably maintaining the fitted condition.
The deflection prevention rib may take any suitable form, and does not always need to extend between the opposite side walls of the detection member body in so far as it can generally fill up a deflection space for the flexible lock arm. Namely, the deflection prevention rib may be interrupted intermediate the opposite side walls of the detection member body, and may comprise two cantilever sections.
In the half-fitting prevention connector of the invention of claim 2 depending from claim 1, the first connector housing has a first projection formed on that portion of an outer peripheral surface thereof facing away from the flexible lock arm, and the fitting detection member has a second projection which is formed on an inner peripheral surface thereof so as to be engaged with the first projection in the completely-fitted condition of the first and second connector housings, and when the first connector housing is completely fitted with the second connector housing, the fitting detection member moves toward the front side of the first connector housing, so that the second projection slides past the first projection, and is engaged therewith.
In the half-fitting prevention connector of this construction, the first connector housing has the first projection formed on that portion of the outer peripheral surface thereof facing away from the flexible lock arm, and the fitting detection member has the second projection which is formed on the inner peripheral surface thereof so as to be engaged with the first projection in the completely-fitted condition of the first and second connector housings, and when the first connector housing is completely fitted with the second connector housing, the fitting detection member moves toward the front side of the first connector housing, so that the second projection slides past the first projection, and is engaged therewith. Thus, the positioning retaining portion is engaged with the detection member-retaining portion, formed at the distal end of the lock arm, and in addition the first projection is engaged with the second projection. Therefore, the force of retaining of the fitting detection member on the first connector housing in the completely-fitted condition increases, thereby more firmly holding the fitting detection member in the proper fitting detection position. And besides, when the first projection and the second projection are engaged with each other, a click feeling is produced, and the completely-fitted condition of the first and second connector housings can be detected also by this click feeling.